I think you meant to say it should stay banned, given your reasoning. But I have to agree, it's built to use its offenses and defenses to basically simulate a Pokemon with 150 in both offensive and defensive stats. Even with new possible checks, as long as King's Shield is in use, you'll get those annoying 50/50 situations. Its varying stats also mean that it can take on a plethora of roles, in both physical and special tanks, as well as more supportive and/or defensive roles, if need be, and while it may do some of these roles better than others, the fact remains that this Pokemon is still a bit of a jack-of-all-trades, making it unpredictable.
However, given the amount of things that would get opened up for speculation, I'm definitely against banning King's Shield for the sake of making Aegislash non-broken. Even with offensive power like that, you'd likely be forced to switch after attacking most of the time. While Ghost/Steel is a lovely typing in and of itself, those 60/50/50 defenses will still be fairly easy to deal with. You'd be open to a plethora of things, and again, being forced to switch is not a good thing. I can't say for certain, but I don't think Aegislash would remain in OU without King's Shield. And then the whole thought process of unbanning something to help balance other potentially broken things gets thrown out the window.
In addition to that, banning a single move because of a single Pokemon seems wrong. I know the only other possible user is Smeargle, but still, you're potentially opening up a can of worms that really doesn't need to be opened. But, the metagame has changed a bit in Aegislash's absence, what with the ORAS Megas and all. The whole point of the suspect test will be to see what it can do now, and whether or not it's still considered broken. I'm personally against it returning to OU, as I don't think the new possible counters can handle it, BUT if it ends up back down there, then I suppose there's enough of a gap in those defenses to take it down easily enough. The real issue here is how it will effect teambuilding again. It's STILL going to be a common Pokemon regardless, and people will STILL need to have an Aegislash counter in mind. The question is whether or not enough of those exist on teams naturally to the point that their just simply there, and will be regardless of its presence. Only time will tell. The clock ticks down more and more each day, and when it finally hits 0, we'll see what happens. But it will be done with Aegislash intact; weakening it by removing its main quality won't solve anything.
